Topology analysis of a power distribution network refers to topology link analysis of an entire network according to power supply nodes, switch nodes and so on by considering the entire network as a topological diagram with a combination of lines and points according to the connection relationship of power distribution electrical elements. The power distribution network conducts other analysis such as state estimation, load flow calculation, fault location, isolation and power supply restoration, and network reconfiguration. Power distribution network has a huge and complex structure, and the network structure often changes due to on/off status of the switches in load transfer operation during a fault.
In this respect, there are presently methods at home and abroad, such as association list matrix representation, network-based matrix representation, node elimination method, tree searching representation and discrete processing method, all of which are developed based on a master station system, have high system requirements and low speed. Therefore, they can not be applied to power distribution terminals and can not meet real time requirements for protection and control by distributed intelligence.
Patent document CN 02116363.4 proposed a method for collecting network topology information for communication network. The method collects network topology information in Internet protocol and is capable of identifying positional relationships among devices in the network. In communication field, it is not accurate since devices are relatively dispersed and are not fixed in positions. However, since power distribution terminal devices in a power distribution network feature relatively fixed number and installation sites and the power distribution network has a particularly high reliability requirement, the method for collecting information on network topology of a communication network disclosed by this patent document is not suitable for a power distribution network.
Distributed intelligent control needs to adapt to real time change in network structure, such as requiring dynamic identification of positions of tie switches for fault recovery, tracking a main network power source for islanding protection, and load pre judgement for load transfer, all of which need to know network topology relationship in real time. Therefore, it is particularly important to invent an application oriented method for identifying a real-time network topology that enables each application to maintain one dynamic network topology for the application.